Growth of GaSb quantum dots on GaAs (111)A

Abstract

We grew GaSb QDs on GaAs (111)A by molecular beam epitaxy (MBE). By atomic force microscopic studies, it was found that large GaSb islands with low density are formed when grown at a relatively high temperature (T_s ∼ 470°C), suggesting the large diffusion length of Ga atoms on the substrate surface. In contrast, GaSb QDs formed at a lower temperature (T_s ∼ 430°C) are much smaller (∼ 39 nm) in diameter and their density is much higher (∼ 5.0×10¹⁰ cm⁻²), originated from the suppression of the Ga diffusion on the substrate surface. We also grew GaSb QDs at various substrate temperatures T_s and examined how T_s affects the QD radius and height. [DOI: 10.1380/ejssnt.2014.304]